Even though it’s nearly wintertime, you’ll feel warm and fuzzy after a visit to TownPool. The Nantucket-based boutique pops up on Boylston Street through Jan. 2, and it’s probably the least fussy, most entertaining shopping experience in the Back Bay.

“We’re a traveling circus,’’ says partner Luke Gutelius, in between instructing a customer on the finer points of mini-golfing. (Yep, there’s a course inside the store, complete with turf shipped up from Georgia. “Top-ranked,’’ he jokes.)

There’s also a ball pit for kids and a wall lined with countless rubber ducks. Customers who identify the duck facing the wrong way win a prize; Gutelius isn’t sure what yet. A welcome mat declares, “This must be the place’’ in canary yellow lettering.

“We’re family-friendly,’’ says Gutelius, who has three kids himself.

Don’t let the zany atmosphere fool you, though: The shop is stocked with offbeat brands for men, women, and kids — some hard to find elsewhere. Guys hoping to make a splash at a holiday party might slip into a suit by Shinesty, known for its “ugly Christmas sweater’’-themed apparel, perhaps paired with a plaid General Knot tie. Preppy ladies will appreciate tennis accessories from Newton-based Ame & Lulu or hand-knit beanies from STIK. And parents of messy children will find salvation with EZPZ bowls, a hybrid placemat-plate that suctions directly to tables, taking the stress out of spills.

“It’s eclectic. We do everything from crazy Christmas suits to $1,000 leather bags,’’ Gutelius says.

Still, Gutelius says this isn’t a mere pop-up boutique. Yes, you’ll find clothing and accessories. But TownPool also hosts events, like a recent fantasy football talk with ESPN’s Field Yates and an upcoming CrossFit demonstration. Spencer Bass is the shop’s director of design — “director of fun,’’ amends Gutelius — and he spent years executing concept design for Ralph Lauren.

All that’s missing is, well, a pool. Gutelius named the store after fond memories spent at the town pool in his hometown of Weston.

“It was a special place for people who grew up in that town,’’ he recalls. “It always resonated. We think of this place the same: ‘Come and meet at the town pool.’ ’’

And play a few rounds of mini-golf before you leave.

Kara Baskin can be reached at kcbaskin@gmail.com.